OP appears to be from Brazil, which does have some big issues with school quality[0]:
> Another problem for Brazil is that it is one of the few countries which does not have good basic educational statistics. Nevertheless, it is clear that too few children go to primary school. To make matters worse, more than a third of children repeat a grade at least once in primary or secondary school. This is particularly true for students from disadvantaged backgrounds. This poor performance at school is linked to a high drop-out rate. Only 88.7% complete basic education and there are more than 600,000 primary age children are out of school.
> For those who do remain at school, performance is poor, reflecting poor school quality. The OECD’s internationally respected PISA survey (Program for International Student Assessment) put Brazil near the bottom of the list of 65 countries taking part, making it comparable to Albania, Jordan and Tunisia.
> Another problem for Brazil is that it is one of the few countries which does not have good basic educational statistics. Nevertheless, it is clear that too few children go to primary school. To make matters worse, more than a third of children repeat a grade at least once in primary or secondary school. This is particularly true for students from disadvantaged backgrounds. This poor performance at school is linked to a high drop-out rate. Only 88.7% complete basic education and there are more than 600,000 primary age children are out of school.
> For those who do remain at school, performance is poor, reflecting poor school quality. The OECD’s internationally respected PISA survey (Program for International Student Assessment) put Brazil near the bottom of the list of 65 countries taking part, making it comparable to Albania, Jordan and Tunisia.
[0] https://www.copenhagenconsensus.com/publication/brazil-persp...